Employee Benefit Plans (Details 2) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) bond	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Noncurrent liabilities	$ 259,367	$ 319,597
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Change in Net Periodic Pension Costs		$ 7,000
Pension Plan
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rates	3.10%	3.90%	3.70%
Expected long-term rates of return on plan assets	6.20%	6.70%	7.00%
Expected long-term rates of return on plan assets for next year (as a percent)	6.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rates	2.80%	3.10%
U.S. Plans | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 305,652	$ 307,390
Service cost	43	102	$ 118
Interest cost	9,878	10,165	12,357
Plan participants' contributions	0	0
Amendments	0	0
Actuarial loss	14,459	5,550
Settlements/curtailments	0	0
Benefits paid	(15,171)	(17,555)
Effect of foreign currency	0	0
Benefit obligation at end of year	314,861	305,652	307,390
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	205,271	208,870
Actual return on plan assets	33,942	11,935
Employer contributions	5,899	2,021
Plan participants' contributions	0	0
Settlements/curtailments	0	0
Benefits paid	15,171	17,555
Effect of foreign currency	0	0
Fair value of plan assets at end of year	229,941	205,271	$ 208,870
Funded status at end of year	(84,920)	(100,381)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Noncurrent assets	1,860	668
Current liabilities	2,237	2,278
Noncurrent liabilities	84,543	98,771
Total accumulated other comprehensive loss before tax	146,341	161,075
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss	146,340	161,042
Prior service cost	1	33
Total accumulated other comprehensive loss before tax	146,341	$ 161,075
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Net actuarial loss	5,203
Prior service cost	1
Total	5,204
Estimate of expected contributions in next fiscal year	9,900
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2018	20,200
2019	19,300
2020	19,200
2021	19,200
2022	19,300
2023-2027	$ 94,100
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rates	4.00%	4.20%	3.90%
Expected long-term rates of return on plan assets	7.30%	7.30%	7.50%
Expected long-term rates of return on plan assets for next year (as a percent)	7.30%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rates	3.50%	4.00%
Number of U.S. dollar-denominated, AA-graded corporate bonds in yield curve universe | bond	700
Highest yield U.S. dollar-denominated, AA-graded corporate bonds excluded from yield curve universe (as a percent)	10.00%
Lowest yield U.S. dollar-denominated, AA-graded corporate bonds excluded from yield curve universe (as a percent)	10.00%
International Plans | Pension Plan
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation at beginning of year	$ 952,360	$ 900,104
Service cost	1,724	1,585	$ 1,648
Interest cost	21,459	26,822	36,282
Plan participants' contributions	61	68
Amendments	(4,459)	0
Actuarial loss	(3,613)	194,469
Settlements/curtailments	(3,362)	(1,527)
Benefits paid	(40,379)	(32,079)
Effect of foreign currency	91,795	(137,082)
Benefit obligation at end of year	1,015,586	952,360	900,104
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	732,743	755,966
Actual return on plan assets	67,136	105,027
Employer contributions	18,187	17,192
Plan participants' contributions	61	68
Settlements/curtailments	(3,241)	(1,527)
Benefits paid	39,800	31,485
Effect of foreign currency	67,631	(112,498)
Fair value of plan assets at end of year	842,717	732,743	$ 755,966
Funded status at end of year	(172,869)	(219,617)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Noncurrent assets	1,820	1,118
Current liabilities	625	505
Noncurrent liabilities	174,064	220,230
Total accumulated other comprehensive loss before tax	427,127	434,868
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Net actuarial loss	430,377	433,626
Prior service cost	(3,250)	1,242
Total accumulated other comprehensive loss before tax	427,127	$ 434,868
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Net actuarial loss	15,186
Prior service cost	(149)
Total	15,037
Estimate of expected contributions in next fiscal year	19,200
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2018	40,100
2019	41,200
2020	42,700
2021	44,500
2022	45,200
2023-2027	$ 247,900
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount rates	2.80%	3.80%	3.70%
Expected long-term rates of return on plan assets	5.90%	6.50%	6.80%
Expected long-term rates of return on plan assets for next year (as a percent)	5.60%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount rates	2.60%	2.80%